One of the reasons that everyone was against the wedding is that divorce is not legal in the Philippines. CJ will be unable to change his mind after the wedding and be stuck with Princess.
As seen from the graduation photo wall scene, Teddie, Alex, and Gabbie are all graduates of University of the Philippines, while Bobbie is the only Salazar sister to have studied and graduated from Ateneo de Manila University. The two universities mentioned are among the four most prestigious universities in the Philippines.